TY - JOUR
T1 - Investigation of the thermonuclear 18 Ne(α, p) 21 Na reaction rate via resonant elastic scattering of 21 Na + p
AU - Zhang, L. Y.
AU - He, J. J.
AU - Parikh, A.
AU - Xu, S. W.
AU - Yamaguchi, H.
AU - Kahl, D.
AU - Kubono, S.
AU - Mohr, P.
AU - Hu, J.
AU - Ma, P.
AU - Chen, S. Z.
AU - Wakabayashi, Y.
AU - Wang, H. W.
AU - Tian, W. D.
AU - Chen, R. F.
AU - Guo, B.
AU - Hashimoto, T.
AU - Togano, Y.
AU - Hayakawa, S.
AU - Teranishi, T.
AU - Iwasa, N.
AU - Yamada, T.
AU - Komatsubara, T.
AU - Zhang, Y. H.
AU - Zhou, X. H.
PY - 2014/1/23
Y1 - 2014/1/23
N2 - The 18Ne(α,p)21Na reaction is thought to be one of the key breakout reactions from the hot CNO cycles to the rp process in type I x-ray bursts. In this work, the resonant properties of the compound nucleus 22Mg have been investigated by measuring the resonant elastic scattering of 21Na + p. An 89-MeV 21Na radioactive beam delivered from the CNS Radioactive Ion Beam Separator bombarded an 8.8 mg/cm2 thick polyethylene (CH2)n target. The 21Na beam intensity was about 2×105 pps, with a purity of about 70% on target. The recoiled protons were measured at the center-of-mass scattering angles of θc.m.≈175.2, 152.2, and 150.5 by three sets of ΔE-E telescopes, respectively. The excitation function was obtained with the thick-target method over energies Ex(22Mg)=5.5-9.2 MeV. In total, 23 states above the proton-threshold in 22Mg were observed, and their resonant parameters were determined via an R-matrix analysis of the excitation functions. We have made several new Jπ assignments and confirmed some tentative assignments made in previous work. The thermonuclear 18Ne(α,p)21Na rate has been recalculated based on our recommended spin-parity assignments. The astrophysical impact of our new rate has been investigated through one-zone postprocessing x-ray burst calculations. We find that the 18Ne(α,p)21Na rate significantly affects the peak nuclear energy generation rate, reaction fluxes, and onset temperature of this breakout reaction in these astrophysical phenomena.
AB - The 18Ne(α,p)21Na reaction is thought to be one of the key breakout reactions from the hot CNO cycles to the rp process in type I x-ray bursts. In this work, the resonant properties of the compound nucleus 22Mg have been investigated by measuring the resonant elastic scattering of 21Na + p. An 89-MeV 21Na radioactive beam delivered from the CNS Radioactive Ion Beam Separator bombarded an 8.8 mg/cm2 thick polyethylene (CH2)n target. The 21Na beam intensity was about 2×105 pps, with a purity of about 70% on target. The recoiled protons were measured at the center-of-mass scattering angles of θc.m.≈175.2, 152.2, and 150.5 by three sets of ΔE-E telescopes, respectively. The excitation function was obtained with the thick-target method over energies Ex(22Mg)=5.5-9.2 MeV. In total, 23 states above the proton-threshold in 22Mg were observed, and their resonant parameters were determined via an R-matrix analysis of the excitation functions. We have made several new Jπ assignments and confirmed some tentative assignments made in previous work. The thermonuclear 18Ne(α,p)21Na rate has been recalculated based on our recommended spin-parity assignments. The astrophysical impact of our new rate has been investigated through one-zone postprocessing x-ray burst calculations. We find that the 18Ne(α,p)21Na rate significantly affects the peak nuclear energy generation rate, reaction fluxes, and onset temperature of this breakout reaction in these astrophysical phenomena.
UR - http://www.scopus.com/inward/record.url?scp=84894556170&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84894556170&partnerID=8YFLogxK
U2 - 10.1103/PhysRevC.89.015804
DO - 10.1103/PhysRevC.89.015804
M3 - Article
AN - SCOPUS:84894556170
SN - 0556-2813
VL - 89
JO - Physical Review C - Nuclear Physics
JF - Physical Review C - Nuclear Physics
IS - 1
M1 - 015804
ER -